Alleged former IRA leader Thomas “Slab” Murphy has been jailed for 18 months for tax evasion.

The 66-year-old bachelor farmer, who denied the charges, owes the Irish exchequer almost €190,000 (£147,000) for tax dodging from 1996-2004.

Murphy, from Ballybinaby, Hackballscross, Co Louth, on the border with Northern Ireland, was found guilty last December of nine charges at the non-jury Special Criminal Court.

Dressed in a pink shirt, brown jacket and slacks, Murphy showed little emotion in the dock as the sentence was delivered.

He acknowledged some family members and friends as he was led out of a side door of the court.

Murphy was sentenced to 18 months for each of the nine counts, with the jail terms to run concurrently.

Judge Paul Butler, presiding in the three-judge court, noted the publicity around the trial but insisted they were not swayed by reports of Murphy’s republican links.

He said: “It has no bearing whatsoever upon the Revenue charges. This court must and does treat the accused as a farmer and cattle dealer with no other connections, past or present.”

The penalties for the offences could have been as much as five years in jail or fines of up to €100,000 (£77,800).

Murphy was sentenced at the high-security court, which normally deals with terrorist and gangland trials, as Ireland votes in a general election.

And the decision of the three-judge court will demand more answers from Sinn Fein leader Gerry Adams over his description of Murphy as a “good republican”.

The farmer, who has no previous convictions and works as a yardsman for a business in Crossmaglen, South Armagh, did not give evidence during the 32-day trial.

He also ignored questions on his way in to hear his fate.

Murphy’s trial heard that his total tax bill for the nine years was €38,519.56 (about £30,000), and interest built up on those unpaid bills was €151,445.10 (about £117,000), taking the final amount owed to €189,964.66.

He was charged with five counts under the Republic’s Taxes Consolidation Act and four under the Finance Act that he knowingly and wilfully failed to make tax returns and did so without reasonable excuses.

The court found he did not furnish Ireland’s Revenue authorities with a return of income, profits or gains or the sources of them over the period but received €100,000 (£73,000) in farm grants and paid out €300,000 (£220,000) to rent land.

In 1998, Murphy lost a £1million libel action against the Sunday Times which described him as a senior IRA figure.

On one of only two occasions when he has spoken publicly, he claimed he had to sell a home in order to pay for some of the costs of the failed lawsuit.